P1605: IMMUNE THROMBOTIC THROMBOCYTOPENIC PURPURA IN OLDER PATIENTS: RESULTS FROM THE SPANISH TTP REGISTRY (REPTT)
Authors: Inés Gómez Seguí, Eva Frances Aracil, Mingot-Castellano Maria Eva, M Vara Pampliega, Rosa Goterris, F García Candel, Cristina Pascual Izquierdo, Julio del Rio Garma, Luisa Guerra Dominguez, Isabel Vicuña Andrés, Jose Garcia-Arroba Peinado, Saioa Zalba Marcos, Julia Vidan Estevez, Elena Gonzalez, Veronica Campuzano Saavedra, Jose Maria Garcia Gala, S Ortega Sanchez, Jorge Martínez Nieto, Laura Pardo Gambarte, Maria Sole Rodríguez, Marta Fernandez Docampo, Laura F. Ávila Idrovo, Luis M. Hernández, Joan Cid, Javier DE LA Rubia
Journal: HemaSphere (2023)

Topic: 32. Platelet disorders Background: Immune thrombotic thrombocytopenic purpura (iTTP) is an ultra-rare disease that seldom occurs in the elderly. Few reports have studied the clinical course of iTTP in older patients. Aims: In this study we analyze the impact of age in terms of clinical and laboratory findings at the time of diagnosis, as well as response to therapy, exacerbations, and refractoriness in a series of 44 patients with iTTP ≥60 years and compared with 209 patients <60 years included in the Spanish TTP registry. Methods: We queried the Spanish TTP Registry for adult patients (>18 years) with iTTP diagnosed between 2002 and 2021. Inclusion criteria were a first episode of iTTP, with a clinical diagnosis of iTTP, initial determination of ADAMTS13 <10%, and presence of ADAMTS13 inhibitors in plasma. Outcome definitions were based on those published by the International Working Group (Scully et al. 2017). Results: Similar symptoms and laboratory results were described in both groups, except for a higher incidence of renal dysfunction among older patients (23% vs. 43.1%; P= 0.008) (Table 1). Every patient received front-line treatment with TPE. Immunosuppressive therapy with steroids (95 vs. 93%) or rituximab (46 vs. 57%) and caplacizumab (23 vs. 32%) was administered equally in both groups (P= n. s. for patients in Group 1 and 2, respectively). Similar rates of clinical response were seen in both groups (184 [88%] patients in Group 1 vs. 38 [86.4%] in Group 2), as well as refractoriness to front-line therapy (25 [12%] vs. 6 [13.6%]). Exacerbation was more frequently observed among elderly patients: 17 (45%) vs. 57 (31%) in the younger age group, although differences were not statistically significant. Twelve patients died (4.7%) after a median follow-up of 14 months (8 - 16 years), [8 (3.8%) in Group 1, and 4 (9.1%) in Group 2]. Seven (2.7%) patients (5 in Group 1 and 2 in Group 2) died during the iTTP episode: six with refractory disease and one had suffered an exacerbation. The remaining five patients died after a median of 23 months (range, 17 – 87) due to infectious and thrombotic complications, including two of them after a relapse. Summary/Conclusion: iTTP in the elderly was similar to younger patients in the acute bout, except for slightly worse renal function, attributable to aging more than to TTP involvement. Novel findings in this cohort include the improvement of prognosis in older patients with iTTP, with similar mortality and response rates. Given the rarity of iTTP in the general population, aggregation of findings from various iTTP cohorts will be of great value for a better knowledge of the clinical picture of iTTP among older patients.Keywords: TTP, Elderly, ADAMTS13, Thrombotic thrombocytopenic purpura (TTP)